He said the two suspects, brothers Dzhokhar and Tamerlan Tsarnaev learned how to construct the bombs from an al Qaeda magazine.

“Brother number two has said they got the information on how to build the bomb from Inspire magazine,” said Ruppersberger, from an article titled “How to build a bomb in your mom’s kitchen.”

The Tsarnaev brothers are accused of packing two pressure cookers full of shrapnel and detonating them last week during the marathon. Tamerlan Tsarnaev died after a shootout with police, but the younger brother is in police custody, hospitalized as he recovers from gunshot wounds.

Ruppersberger also said that the brothers had used explosives they purchased at a fireworks shop in New Hampshire.

“One of the brothers, the oldest brother, went to a shop in New Hampshire ... and asked for the most volatile explosives, so that you'd 'get the best bang,’ ” he said.

The latest details about the bombing come as investigators continue to piece together the Tsarnaev brothers’ actions leading up to the deadly attack.

Dzhokhar Tsarnaev, who has been charged in the attacks, acknowledged his role in carrying out the bombings, two unidentified officials told the Associated Press on Wednesday.

House lawmakers have also scheduled hearings to probe if the FBI, which had been alerted to the older brother’s possible ties to Islamist extremists, failed to miss critical red flags which could have prevented the attack beforehand.

Speaker John BoehnerJohn Andrew BoehnerRestoring fiscal sanity requires bipartisan courage GOP congressman slams primary rival for Ryan donations Speculation swirls about Kevin McCarthy’s future MORE (R-Ohio) vowed on Wednesday to “get to the bottom of this,” and raised questions about whether intelligence agencies and law enforcement had failed to properly share information.

The Department of Homeland Security was aware of a trip Tamerlan Tsarnaev took to volatile regions of Russia plagued by jihadi violence, but the FBI which spoke to him before the trip after being tipped by Russian investigators did not interview the older brother upon his return.